Mixing machine



MIXING MACHINE A TTORNEYS 2 ,M O /Q 1N VENTOR l A TTORNE YS Feb. 18,1930,v

H.,L JoHNs-roN MIXING MACHINE Filed Nov. so, 192s- 2 sweets-sheer l 2 vigsvBY . Perenpted Feb. 18,1930

UNITED STATES;

PArENTgorl-"ICE l HERBERT L. JOHNSTON, OF TROY, OHIO,'ASSIGNOR TO THE HOBART 'MANUFACTU ING COMPANY, OF TROY, OHIO, A CORPORATION OF OHIO 1 MIXING MACHINE Application filed November 30, 1928. Serial No. 322,859.

This xinvention relates to mixing machines and particularly to machines for mixing foodstuifs such as bread dough and the like.

The primaryl object of the invention is the 5 provision of av mixing machine of this character adapted to be operated with a minimum of attention, and which may be easily controlled by the operator. p

Other objects and advantages of the invention will be apparent from the following description when taken in connection with the accompanying drawings.

In the drawings, Fig.- 1 is a side elevation of a mixing machine embodying the present invention, shown with parts broken away disclosing the driving mechanism; and

Fig. 2 is a vertical section through the supporting pedestal on the line 2--2 of Fig. 2.

Referring'more particularly to the drawings in which like characters of reference represent corresponding. parts in the various iigures, the machine is comprised essentially of a base 10 upon which is mounted a supporting pedestal 11 which holds the supporting table 12 in which is mounted the mixing bowl 13', At the upper part of the pedestal is the gear or transmission mechanism by means of which the electric motor 14 is connected to the revolving mixing arm 15. The mixing arm 15 ,is preferably so operatedthat it rotates about its own axis while moving bodily about in the lmixing bowl. Suitable operating mechanism'is provided by means of which the loperator is permitted to control the starting and stoppin of themachine and to control the speed `o operationthereof.4 .'Ifhiscase however is particularly concerned with the elevating mechanism for the mixing bowl,

.the present casebeing a division of my'prior application for Letters Patent entitled Mix- 'ing machine, Serial No. 196,785, filed Junethe table'12 which is adapted to be vertically adjusted so as to raise or lower the bowl to permit its removal or to adjust the extent to V which the mixing arm 15 ,fextends into the bowl. f

The pedestal 11 is provided with a front flat bearing surface 250 aga-inst which bears the rear flat bearing surface 251 of the supporting rack post 252. JThe rack post has side y portions 253 which extend around the sides of the bearing surface 250 ofx the pedestal.

4The upper portion of the rack post forms a 'close engagement throughoutits trans erse extent with the front surface 250 so t particles or other materials being not be permitted to get between the rack post 252 and the bearing surface 250. lThe rack ood post carries a vertical rack 254 which is at# tached by means of the screws 255 and which is provided with inwardly projecting teeth 256 adapted toengage with the teeth of a pinion 257 mounted on a shaft 258 extending through the pedestal and bearing a gear 259 in the interior of the hollow pedestal 11., The

shaft 258 is mounted in Suitable bearings in the pedestal and the pinion 257 is located in an open space 260 in the bearing surface 250 of the pedestal. The pedestal bearing surface 250 is therefore enclosed on the top and sides by the rack post 252 sothat in case of splashing of the material being perated upon in the bowl there would be no. tendency for thesev ixed willl splashes to find their way -into the insideof the pedestal and to cause a foul or unsanitary condition to exist.

' The upwardand downward movement of the rack post 252 is limited at its upper and lower limits of movement by the limiting stops or lugs 270 and 271 provided at the up` per and lower portions of 'the pedestal in t e path of movement of the upper and lowerportions of the rack post 252. The vertical movement ofthe rack post and the bowl-supporting table is accomplished by rotation of the pionion 257 which is operated by the ear 259 meshing with the idler gear 27 5 w vich serves as a/worm-wheel and is adapted to be operated by means of the worm 276 above it. The idler gear 27 5-is mounted upon ashaft 277 fixed pn'the pedestal in any suitable manl nerl and the worm which engages'this 283 each of ywhich engages at one side with aidler gear lcauses the rotation of the gear train to elevate or depress the bowl. The worm 276 is keyed on the control shaft 2 80 by means of the key 281 but is otherwise free to move longitudinally alongthe shaft ex-l cept as restrained by the'two springs 282 and.

collar 284 mounted` freely' on the shaft 280 i l normal raising or ylowering of the bowl, they Yin contact'with a shoulder. on thegear and at its other end with the fixed collar 285' which is fixed to the shaft 2SC-by means of a' pin 286. The springs 282 and 283 thus maintain the'worm 276 in a normal central position on the shaft 280'and these springs are on the side of the machine where it can be easily adjusted by the operator -or the purpose of'rotating the gear train to elevate and depress the bowl. Although the s rings 282 and-283 which center the worm 2 6 and normally maintain it in engagement with the idler gear 275 are suiiiciently strong to prevent .excessive endwise movement of the worm 276 during'th'e are adapted to yield when the bowl has vbeen raised to its upper or lowered to itslowermost level and-abuts against the stops 270 or'271.v In case the operator continues-to apply. force to the control wheel 287 afterthe rack post. 252 has come into engagement with one or the -other of the limiting stops the'springs 282 and 283will permit the operator to continue yto rotate the hand-'wheel 287 against ever increasing pressure of these. springs without jamming the geartrain and without further jamming the supporting'A rack posty against vthe limitin stopsa The-mcreasn resistance on the han -wheel by 'reason o f t e compres-v sion of .one of the springs 2824 nd 283 .will immediately notify "the opera r that 'he should stop the rotationvfof fthe v hz'm'd-wheel.'

However, 1f he continues to rotate thehand-z wheel the worm 276 will merely mo vendwise alongA the shaft 280 without ,causing any rotationofthe gear'train with which it isreligaed. a i

' It now be apparentthatthe raising and lowering movements of the bowl may be readilyeected. Operation of the handl" wheel 287 vin one-direction causes the bowl to `be raised to cooperative association .with the mixing arm 15. .After the materialhas been.

beaten or mixed, the hand-wheel 28'(y is again Voperated but in the reverse direction to cause .thailqwer'ing of.. the, bm'v1-smhafit-niay 'bel readily removed from. the table 12.

-erating said mechanism and a the -form of apparatus herein de'- scribed constitutes a preferred embodiment of the invention, it isto be understood that the invention is not limited to this precise form of apparatus, and that changes may be.

made therein without departing -from the scope of the invention which is defined in the ap ended claims.

hat is claimed is: l. In a mixing device of the class described, a'n elevating `mechanism comprisltal, a slide face on said pedestal, a slide adjustable along-saidface, a rack on said slide and a pinion rotatably mounted on said pedestal and lying atwise relatively to the slide and in engagement withsaid-rack.

3. In a device of the class described, a pedj estal, a support vertically movable along said pedestal, inwardly-extending rack teethon. the inner side of saidsupport, a pinion on the outer sideof said pedestal engaging said rack teeth, and a shaft for said' pinion extending into said pedestal, and means for operating said shaft. "1

4. In a device of the' class described, a pedestal, a support vertically movable along said theI inner side of 'said' support, a pinion on `the-outer side of said-pedestal engaging said rack teeth, and a shaft. for said pinion extending `into said pedestal, means for operating said shaft, and resilient means for preventing'jamming of said means.

- 5. In a -device of ,theclass describe.d,'a pedestal, a bowl support vertically movable alon saidpedestal, operating means for said bow support whereby it maybe moved in opposite directions along said pedestal, said operating means including resilient means preventing jamming of the operating means. v

6. In a device of the class described, a d estal, a bowl support vertically slidable a olg said pedestal, operating mechanism for sli in said bowl supportup and down on said pe estal, self-locking operatinf means for opual operation, Aand resilient means preventing )amming of said operating means.

. 1; In-av device of the class described, a pedestal, a support vertically movable along said 11m l pedestsl, andmeans for movinl said support l comp'risinl a hand-operated aft, a worm operated' y said shaft mounted capable of' endwise movement, .and spring means normally holding said worm in normal sition.

' 8. In a device of the class describe a pedestal, a support vertically movable along said .pedestal and means for moving said sup rt sbagliJ a comprising .a manually controlled worm-wheel, a' worm engaging said wormapted for man f wheel and rotated by said shaft, said worm being capable of endwise movement2 spring means normally holding said worm 1n operating position in' engagement with said wormwheel, said 'spring means maintaining said worm and worm-wheel engaged for. normal operation but permitting rotational move- Vments of the worm without corresponding rotational movements of the Worm-wheel.

9. In a mixing device of the class described, a pedestal, a slide face on said pedestal, a bowl supporting slide adjustable along'said slide face, and operating means for raising and lowering the slide said means being enclosed and protected by vsaid slide in various positions of the slide on the slide face.

In testimony whereof I hereto aix my signature.

HERBERT L. JOHNSTON. t 

